Technology of manufacturing a semiconductor device by bonding a semiconductor wafer on which a semiconductor device is formed (hereinafter referred to as device wafer) to a semiconductor wafer which supports the device wafer (hereinafter referred to as support wafer) is conventionally disclosed. The device wafer is thinned in a state in which the device wafer is bonded to the support wafer, so that film thickness of the device wafer is adjusted to be desired film thickness.
A thinning step of the device wafer is performed while a surface of the support wafer is fixed on a chuck table of a grinding device, for example. Therefore, in the thinning of the device wafer, variation in film thickness of the support wafer directly affects the film thickness of the device wafer. The variation in film thickness of the device wafer affects a property of a semiconductor device formed on the device wafer. Therefore, a method of manufacturing a semiconductor device capable of thinning the device wafer while reducing the effect of the variation in film thickness of the support wafer is desired.